# MP4 to FLV Converter Convert MP4 video files to FLV format > Canonical page: https://elysiatools.com/en/tools/mp4-to-flv - **Category:** Media - **Keywords:** mp4, flv, convert, video, format, ffmpeg, flash, streaming, web ## Overview Convert MP4 videos to FLV (Flash Video) format. FLV is widely used for streaming on web platforms and provides good compression with reasonable quality. ## Inputs - **MP4 Video File** (file): Select MP4 video to convert - **Video Codec** (select) - **Audio Codec** (select) - **CRF Quality (18-28, lower is better)** (number): Only applies when re-encoding. 18-28 is recommended range ## When to use - When you need to prepare video content for legacy web players or streaming servers that require the FLV container format. - When you want to re-encode MP4 videos using specific codecs like H.264 or FLV1 to ensure compatibility with older media systems. - When you need to compress MP4 files into smaller FLV files by adjusting the Constant Rate Factor (CRF) quality settings. ## How it works - Upload your MP4 video file (up to 100MB) using the file selector. - Select your preferred video codec (such as H.264 or FLV1) and audio codec (such as AAC or MP3). - Optionally set a CRF quality value between 18 and 28 to control the output file size and visual fidelity. - Click the convert button to process the video and download the resulting FLV file. ## Use cases - Converting modern MP4 recordings to FLV format for integration into legacy RTMP streaming workflows. - Re-encoding high-definition MP4 videos with H.264 and AAC codecs inside an FLV container for web-based flash players. - Reducing video file sizes by converting MP4s to FLV with a custom CRF quality setting for bandwidth-constrained environments. ## Frequently asked questions ### What is the maximum file size I can upload? You can upload MP4 video files up to 100 MB in size. ### Which video codecs are supported for the FLV output? The converter supports H.264, FLV1, H.265/HEVC, and MPEG-4 video codecs. ### How does the CRF quality setting work? The Constant Rate Factor (CRF) controls video quality during re-encoding. Values range from 18 to 28, where lower numbers yield higher quality and larger file sizes. ### Can I convert the audio track to MP3? Yes, you can select MP3, AAC, or PCM 16-bit as the audio codec for your output FLV file. ### Does this tool support batch conversion? No, this tool processes one MP4 video file at a time. ## Related tools - [AVI to MP4 Converter](https://elysiatools.com/en/tools/avi-to-mp4): Convert AVI video files to MP4 format - [FLV to MP4 Converter](https://elysiatools.com/en/tools/flv-to-mp4): Convert FLV video files to MP4 format - [MKV to MP4 Converter](https://elysiatools.com/en/tools/mkv-to-mp4): Convert MKV video files to MP4 format - [MOV to MP4 Converter](https://elysiatools.com/en/tools/mov-to-mp4): Convert MOV video files to MP4 format - [MP4 to AVI Converter](https://elysiatools.com/en/tools/mp4-to-avi): Convert MP4 video files to AVI format - [MP4 to MKV Converter](https://elysiatools.com/en/tools/mp4-to-mkv): Convert MP4 video files to MKV format - [MP4 to MOV Converter](https://elysiatools.com/en/tools/mp4-to-mov): Convert MP4 video files to MOV format - [MP4 to WebM Converter](https://elysiatools.com/en/tools/mp4-to-webm): Convert MP4 video files to WebM format ## Samples - [Video AV1 Samples](https://elysiatools.com/en/samples/video-av1-samples): Sample video files encoded in AV1 format - [Video H.264 Samples](https://elysiatools.com/en/samples/video-h264-samples): Sample video files encoded in H.264 (AVC) format - [Video H.265 Samples](https://elysiatools.com/en/samples/video-h265-samples): Sample video files encoded in H.265 (HEVC) format - [Video Samples](https://elysiatools.com/en/samples/video-samples): Sample video files in different formats and orientations ## Related content - [Audio Encoding and Format Conversion Tools](https://elysiatools.com/en/hubs/audio-convert): Compare audio format conversion, bitrate changes, sample-rate conversion, codec swaps, and export tools in one hub for delivery and archive workflows. - [Video-to-Audio and Animation Conversion Tools](https://elysiatools.com/en/hubs/video-convert): Compare tools that turn video into audio, extract video streams, and convert between short-form video and animated image formats in one hub. - [Audio Editing and Cleanup Tools](https://elysiatools.com/en/hubs/audio-utility): Compare audio trimming, silence removal, fades, mixing, and denoise tools in one hub for podcast, voiceover, and music cleanup workflows. - [Video Preview, Extraction, and Subtitle Tools](https://elysiatools.com/en/hubs/video-utility): Compare video preview generation, stream extraction, audio extraction, subtitle translation, and quick flip tools in one hub for lightweight video prep workflows.